Two 13-metre (43 ft) high stone towers, built in 1694 as bastions of the fort, still remain and are among the oldest structures on the Island of Montreal.

François Vachon de Belmont was sent to New France towards 1680 by his superiors, order of Saint-Sulpice priests in Paris to stop the spread of witchcraft and visions at the mission.

In the two decades of its existence, the brandy trade had increased significantly and the missionaries found it necessary to relocate their neophytes and catechumens farther from the drunkenness and seduction of the cities.

[4] The mission at de la Montagne was closed in 1705: the grounds were rented to the local peasants, and some would live in the fortifications.

The fort contained four bastions and a series of ramparts and palisades, which were all destroyed in 1854 except for the two southern towers, during the building of the College of Montreal.